VengerSatanis, I would love to learn more about your Cha’alt. Please direct me to the right place. Also, does it come in hard copies?Cthulhu bless you for mentioning Cha'alt!
I recommend “Barrowmaze Complete” and “The Forbidden Caverns of Archaia”. These are both from Greg Gillespie, available on DriveThruRPG, pdf’s or POD Hardbacks.
Barrowmaze is vastly superior to Caverns of Achaia.
Another 5e megadungeons is Grande Temple of Jing.
If you also want to include OSR, the list is very long.
Has anybody looked at Highfell: The Drifting Dungeon by Greg Gillespie? I was just looking for reviews of this. The price is pretty steep, but looks like a lotta fun.
Here’s one review if anybody’s interested Highfell